In recent years, various peripheral equipments such as household electric appliances and personal computers have been connected to a network. It will be made possible to connect a mobile terminal of a cell phone, a PDA, etc., possessed by the user and peripheral equipments wirelessly and enable the user to easily use the peripheral equipments in the vicinity of the user with the development of short distance wireless technologies of Bluetooth (registered trademark), UWB (Ultra WideBand), etc.
A network where a mobile terminal and peripheral equipments existing in the vicinity of the mobile terminal are connected by short distance wireless signal is called PAN (Personal Area Network). The mobile terminal and the peripheral equipments existing in the PAN are operated in cooperation with each other, whereby highly convenient service for the user can be realized. For example, it is made possible to realize a videophone, etc., using a large-sized TV in the PAN in place of a small screen of the mobile terminal as a display.
On the other hand, to establish communications between terminals, information concerning the capabilities of the terminals (capability information) is exchanged between the terminals and communications are conducted using which capability, namely, what service is realized between the terminals is determined. Generally, this procedure is called capability exchange. The possible types of capability information exchanged in the capability exchange are the types of codec and applications that can be used in the terminals, information concerning the device capabilities of the screen size, the CPU speed, etc. For example, if the codec types of audio and moving image as capability information are exchanged, one or more codecs to be used are determined from among the exchanged capability information pieces and transmission and reception of a media stream using the codec are realized as service between the terminals.
To realize communication service using peripheral equipments as components of a PAN by a mobile terminal, not only the capability information of the terminal, but also the capability information of the peripheral equipments that can be used in the PAN needs to be exchanged with the communication party to determine the service to be realized and the machines to be used.
In an art described in non-patent document 1, a terminal for conducting capability exchange conducts capability exchange with the communication party containing not only the capability information of the terminal, but also the capability information of the peripheral equipments in the PAN, thereby making it possible to select an appropriate machine and start or switch communications.
Non-patent document 1: “Implementation and analysis of a resource selecting/switching mechanism using SIP under Ubiquitous resource environment” March 2004, Naoki IMAI, Manabu ISOMURA, Hiroki HORIUCHI, in the 66th conference of Information Processing Society of Japan, 3H-4, 3-219 pages